1. Field of the Invention
The present invention relates to an image display apparatus and an image display method for displaying an image by projecting light onto a projection surface. Particularly, the present invention relates to an image display apparatus and an image display method for displaying an image by projecting a laser beam onto a projection surface.
2. Description of the Background Art
In recent years, development of laser projectors for displaying an image by projecting a laser beam onto a projection surface such as a screen has advanced. To display an image appropriately with a laser projector, it is important to detect the intensity of a laser beam emitted by a laser and the position of a scanning element scanning the laser beam on a projection surface, and to determine scanning timing.
Patent Document 1 (Japanese Patent Laying-Open No. 2007-147728) discloses an image display apparatus including an optical detector that obtains a signal for detecting the amount of light emitted by a laser and also obtains a signal for detecting the position of a holder holding a lens and a polarizing plate.
Further, an image display apparatus disclosed in Patent Document 2 (Japanese Patent Laying-Open No. 2006-323035) includes a linear detector detecting the position of light emitted from a light source for detecting a mirror angle and reflected by a scanning mirror. The image display apparatus controls driving of the scanning mirror based on a detection signal of the linear detector.
Patent Document 3 (Japanese Patent Laying-Open No. 2003-270563) discloses an image display apparatus including a light source outputting synchronization detection light provided independently of a light source outputting a scanning light beam eventually projected onto a screen, and a light receiving unit detecting the synchronization detection light. An output signal output from the light receiving unit is converted into a synchronization signal. Further, the synchronization signal is converted into a scanning start signal.
An image display apparatus disclosed in Patent Document 4 (Japanese Patent Laying-Open No. 2007-193337) includes an optical sensor sensing the amount of off-light not used for image display. The image display apparatus corrects optical output of a light source in accordance with a sensing result of the optical sensor.